LED devices have experienced rapid growth. An LED device, as used herein, is a semiconductor light source for generating a light at a specified wavelength or a range of wavelengths. An LED device emits light when a voltage is applied across a p-n junction formed by oppositely doped semiconductor compound layers. Different wavelengths of light can be generated using different materials by varying the bandgaps of the semiconductor layers and by fabricating an active layer within the p-n junction.
LED devices are traditionally used for indicator lamps, and are increasingly used for displays and general lighting. As a new generation light source, LED devices are capable of replacing incandescent lamps, fluorescent lamps and high-intensity discharge lamps. When compared to incandescence light sources, LED devices offer advantages such as reduced power consumption, longer lifetime, faster response speed, more compact size, lower maintenance costs, and greater reliability. LED devices have thus found many applications, including backlighting for displays, automotive lighting, general lighting, and flash for mobile cameras.
Thermal management for LED devices, especially for high bright LED devices (HBLEDs) is important to these LED devices' performance and lifetime. Thermal management may be implemented by techniques of enhancing heat dissipation and reducing heat production. To enhance heat dissipation, developments have been made in areas such as heat sink, printed circuit board (PCB) as well as LED packaging. Thermal protection structures are also used to prevent overheating of LED device during their operation. However, traditional LED thermal protection structures may not function well when a plurality of LED devices are used in a lighting module. Therefore, while existing LED thermal protection structures have been generally adequate for their intended purposes, they have not been entirely satisfactory in every aspect. Methods and designs that improve the temperature detection accuracy and prevent overheating situations in a plurality of LED devices continue to be sought.